The present invention relates to a silver halide color photographic photosensitive material and a method of forming color images. More particularly, the present invention relates to a silver halide color photographic photosensitive material which is superior in image sharpness, is less deteriorated in performance in a long-term storage thereof, and is capable of forming high quality images and to a method of forming color images using this photosensitive material.
Color photography is a process of producing dye images achieved by using a photosensitive material comprising a support having thereon photographic structural layers comprising a silver halide emulsion and dye forming couplers. The photosensitive material is subjected to development processing with an aromatic primary amine color developing agent, resulting in production of an oxidation product of the developing agent. The dye images are formed by reaction of this oxidation product with the dye forming couplers.
Simplified and rapid color development processing is a strong requirement of the color photographic field and various improvements have been achieved. Advanced faster systems have been developed one after another in a cycle of a few years.
To increase a processing speed requires a further approach to shortening time for each of color development, bleach-fixing, washing with water and drying processes. A method of increasing the processing speed is disclosed in, for example, International Patent Publication No. WO 87/04534. This publication discloses a method of rapid processing by using a color photographic photosensitive material comprising high silver chloride emulsion. From the viewpoint of the rapid processing, it would be preferable to use the high silver chloride emulsion.
Such efforts yield a technique of printing images of a color negative on a silver halide color photographic printing paper for high silver chloride printing, which has become a common method for simple and easy production of high-quality images.
In recent years, diversified requirements of the consumer have led to availability of prints of various sizes enlarged at a high rate such as a panorama or high-vision size. Studies have thus been conducted to further improve, rather than to deteriorate, quality of the images including sharpness even in a print enlarged at a high rate.
Various methods are known to improve the sharpness of the silver halide photographic photosensitive material comprising a reflective support. Examples of such methods are: 1) to avoid irradiation by using water-soluble dyes; 2) to avoid halation by using colloidal silver, mordant dyes or particulate solid dyes; and 3) to increase a fill of white pigments in a laminated resin on a paper support or to avoid transmission of light to the support by means of applying the white pigments dispersed in a gelatin to the support as an additional layer.
Of these, the methods 1) and 2) involve adverse effects such as significant deterioration of sensitivity and residual color in processing. On the other hand, for the method 3), JP-A-57-64235 (the term "JP-A" as used herein means an "unexamined" published Japanese patent application), JP-A-62-187846, and U.S. Pat. No. 4,558,002 disclose that the sharpness can be improved significantly by applying a white pigment dispersed in gelatin on a support. However, the white pigment dispersed in the gelatin deteriorates durability and storage stability of the photosensitive material. In addition, the method increases a total thickness of the layers laminated on the support. As a result, other problems occur including deterioration of processing fluctuation, lack of suitability for rapid processing due to an elongated drying time, and increase in costs. Further improvement is therefore required make this method practical.
JP-A-3-156452 and JP-A-3-156439 disclose that the sharpness can be improved significantly by means of increasing a content of a white pigment in a polyolefin laminate on a support. However, manufacturing cost rises with the increased content of the white pigment in the polyolefin, which restricts practical applications of this approach. On the other hand, JP-A-49-30446, JP-A-2-58042, JP-A-1-142549, JP-A-4-256947, and JP-A-4-256948 disclose a reflective support comprising two or more polyolefin layers having different contents of a white pigment. This approach has been found to be favorable by the economical considerations because the above mentioned structure permits a decreased amount of the white pigment used while maintaining the sharpness.
The present inventor had studied silver halide color photographic photosensitive materials, in particular color photographic printing papers, capable of forming images which are excellent in sharpness. As a result, it has been revealed that a high sharpness can be obtained with less amount of white pigment by using a reflective support having two or more layers which are coated with a water-proof resin and which have different contents of the white pigment. As the photosensitive material is stored over a long period of time, it becomes more likely for desensitization due to pressure applied to the photosensitive material to occur.
Accordingly, an object of the present invention is to provide a silver halide color photographic photosensitive material which is superior in image sharpness, and is less deteriorated in performance in a long-term storage thereof as well as to provide a method of forming color images using this photosensitive material.